There is some concern that bilberry might slow blood clotting. Taking bilberry along with medications that also slow clotting might increase the chances of bruising and bleeding. However, there is not enough information to know if this is a serious concern.

Dosing considerations for Bilberry.

The typical dose of the dried, ripe berries: 20-60 grams daily. People also drink a type of tea made from 5-10 grams (1-2 teaspoons) of the mashed berries.

A dose of 160 mg of bilberry extract taken twice daily has been used in people with diseased retinas.

Bilberry leaf is commonly used as a tea. The tea is prepared by steeping 1 gram, 1-2 teaspoons, finely chopped dried leaf in 150 mL boiling water for 5-10 minutes, and then straining. Don't use bilberry leaf long-term.